/*
 *Copyright © 2018 anji-plus
 *安吉加加信息技术有限公司
 *http://www.anji-plus.com
 *All rights reserved.
 */
package com.anjiplus.template.gaea.business.util;

import org.apache.commons.lang3.StringUtils;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import java.math.BigInteger;
import java.util.Base64;

public class AESUtil {

	// 算法
	private static final String ALGORITHMSTR = "AES/ECB/PKCS5Padding";

	private static final String AES_KEY = "AnjiPLUSAjReport";

	/**
	 * 获取随机key
	 * @return
	 */
	public static String getKey() {
		return AES_KEY;
	}

	/**
	 * 将byte[]转为各种进制的字符串
	 * @param bytes byte[]
	 * @param radix 可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制
	 * @return 转换后的字符串
	 */
	public static String binary(byte[] bytes, int radix) {
		return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数
	}

	/**
	 * base 64 encode
	 * @param bytes 待编码的byte[]
	 * @return 编码后的base 64 code
	 */
	public static String base64Encode(byte[] bytes) {
		// return Base64.encodeBase64String(bytes);
		return Base64.getEncoder().encodeToString(bytes);
	}

	/**
	 * base 64 decode
	 * @param base64Code 待解码的base 64 code
	 * @return 解码后的byte[]
	 * @throws Exception
	 */
	public static byte[] base64Decode(String base64Code) throws Exception {
		Base64.Decoder decoder = Base64.getDecoder();
		return StringUtils.isEmpty(base64Code) ? null : decoder.decode(base64Code);
	}

	/**
	 * AES加密
	 * @param content 待加密的内容
	 * @param encryptKey 加密密钥
	 * @return 加密后的byte[]
	 * @throws Exception
	 */
	public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		kgen.init(128);
		Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
		cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), "AES"));

		return cipher.doFinal(content.getBytes("utf-8"));
	}

	/**
	 * AES加密为base 64 code
	 * @param content 待加密的内容
	 * @param encryptKey 加密密钥
	 * @return 加密后的base 64 code
	 * @throws Exception
	 */
	public static String aesEncrypt(String content, String encryptKey) throws Exception {
		if (StringUtils.isBlank(encryptKey)) {
			return content;
		}
		return base64Encode(aesEncryptToBytes(content, encryptKey));
	}

	/**
	 * AES解密
	 * @param encryptBytes 待解密的byte[]
	 * @param decryptKey 解密密钥
	 * @return 解密后的String
	 * @throws Exception
	 */
	public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		kgen.init(128);

		Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
		cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), "AES"));
		byte[] decryptBytes = cipher.doFinal(encryptBytes);
		return new String(decryptBytes);
	}

	/**
	 * 将base 64 code AES解密
	 * @param encryptStr 待解密的base 64 code
	 * @param decryptKey 解密密钥
	 * @return 解密后的string
	 * @throws Exception
	 */
	public static String aesDecrypt(String encryptStr, String decryptKey) throws Exception {
		if (StringUtils.isBlank(decryptKey)) {
			return encryptStr;
		}
		return StringUtils.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
	}

	/**
	 * 测试
	 */
	public static void main(String[] args) throws Exception {
		String randomString = getKey();
		String content = "report";
		System.out.println("加密前：" + content);
		System.out.println("加密密钥和解密密钥：" + randomString);
		String encrypt = aesEncrypt(content, randomString);
		System.out.println("加密后：" + encrypt);
		String decrypt = aesDecrypt(encrypt, randomString);
		System.out.println("解密后：" + decrypt);
	}

}
